Goals for the coming year: 1. To identify and develop a routine assay for products of N-nitroso compound metabolism, such as methanol, N2 and alkylation products. 2. To investigate effects of incubation time, inhibitors and microorganisms on decomposition products of N-nitroso compounds. 3. To investigate mutagenesis by other N-nitroso compounds and compare with those compounds already tested. 4. To attempt to activate N-nitroso compounds to mutagens using a chemical activation system. 5. To continue efforts to purify the components of the mixed function oxidase system, cytochrome P-450 and P-450 reductase. 6. To measure lifetimes of the proximate mutagens of additional N-nitroso compounds.